I changed fuel filter on Komatsu D31 yesterday. When I tried to use the hand primer pump I couldn’t get it to function. I tried to unscrew the knurled top handle but I could not get the stem to release so I could pump out air, it seems that the pump is stuck. Anyone had luck replacing just the pump and not the entire pump assembly?
I don't have a parts book no days but you can buy the hand pump by itself. I think there are three bolts that hold it to the injection pump.